Regulator for air-pumps.



PATENTED MAY 29, 1906.

I W. HILDEBRAND.

REGULATOR POB. AIR PUMPS.

APPLIGATION FILED JUNE 1905.

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vPALTUENT oiiuon NEAR BERLlN,

seeeuneroe Foe sin-Pumps no. celere.

Specification of Letters Patent.

' latented. May 29, 1906.

pplicution filed June 6, ll. Serial Nu263.964. f

.To a/ZZ whom t may cosi/cern.-

Be it known that 1WLuI-1LM HILDEBRND, en fineer, e German subject, residin fit-Nm 14 ismerc-kstresse, Gross-Lichterfe de, neer Berlin, German Empire, lieve invented new and useful Improvements in Reguletorsfor Air-Pumpe, oi which the following is e specification.

My invention reletes toen' improved re'guw letor 'for oir-pumps, more perticuleriy those which ere employed ior sir-brakes,

The reguletin -velves ordinarily employed for cutting ofi t 1c ump on e certain prede termined pressure eing reached-inthe main reservoir and for egein opening the passeg'e on the pressure sinking are generelly actuated by e piston which is loaded on the one side by the pressure inthe mein cir-reservoir and on the other side is acted upon' by e" spring the tension` of which determines the extent of normal pressure inA the reservoir.

i in the cese of directrocting brakes it ie, further, the o'enerel practice to connect the spring-loederlside of the piston with the mein pipe so that the pressure existing in this let ter during tlieprocess oi braking lassists the spring, and thus connectstlie pu'iiip on eecli' occasion of braking.. is ettended Witlithe disedvente c that in the event ofi raking for o consi ereble time regulation of the sir-pressure in the reservoir is prevented, since the brekingrassure, which in certain ceses may approec "to thet of the pressure in the reservoir, acts on the entire surface of the piston, on which, on the lother side, the reservoir-pressure acts.' Furtberinore, this method of ectueting the' Pump-regulator in tlie cese of automatic brakes, and in particular .with double-chmu-` ber brckes, (genoot be employed, since With sucio tbe -breite-pme 'le elweysiilled with cir.

' According to my'invention eil these defects ere overcome by' connecting tbe legulatorfpiston or other movable surlece suoli as die.-

ploregns, wit-ne second movable surfacev ci? v piston exposed to theulbressure in the pipe,

which seeondlurfece is' oi smaller diameter.,

. l 1 v than the rsteinen suriece or mem xston in order to pre nt undue increase of t 1e res`` erven-pressurewhen the' broke is ep lied for e considerable period of time. Int 's :men-V nor by slight increase. of the pressure in the reservoir the action of the auxiliary surface" is equelized and the iintin surface is enabled 'liiis method, however,

Aton The spring-pressure opposes to properly regulate'` the reservoir-pressure Vegeunst the pressure on the auxiliary surface.

- ln the accom en 'ng drawings, Figure 1 sliows e longitu ineioction oi'u pum -rcgulater for automatic eirfbmles, und ig.` 2 s. like view of'such e reguletor for direct-acting einbrakes. I

ln the reguletor-cosing fi c2 c3 cit-two surr feces or pistons' b 'ende ereloceted, working,

respectively, in 'tue' 'clienibers c end e* and connected yrv the rod d. yln the. elidemlve chamber o there is located e slide-velero e,

'which is actuated' fingers or lu s projectertare A.. Ol' the two pesseges B C the ormer, B', conducts to thecut-o'l device for connecting enddisconnecting the' source of 'sir-viz., the pump. The other passage C conducts to the atmosphere. VThe chamber 2 communicates with Vthe etmosphereand contains the spring which acts on the se forceexertedon the pistbn by the reservoir.-

pressure endis odnpted't'e the normal pressure ofthe reservoir. The chamber 3 is connected with the brekelpipe D, so the; the

pressure in the letter 'iicts upon the piston c:

The manner of operation is es followsJ reference .being hrst made to the sutomctlm brake, Fig. l: The tension of the spring is.

so adjusted as .to exceed the forces exerted 'A upon the pistons b und c by the reservoir end pipe pressure so long es the normal reservoirpressure has not been etteined. '.ihepist.r

system is thus forced toward the left, sotliat t 1 e passe es B eni C cre connected by the liollowed ece Ao the valve e. The pumpout ofi device is brought into communication' With the atmosphere end the pump connect# ed. The ressure inthe main reservoir rises' ing on the differential piston o, together with the plpe-pressure acting on'the piston c, overcomes the forceof the spring end drives the loo 'according y until the mein pipe-pressure actpiston-'system toward the right. The pssrflf 'I r3/,sure acting on the left-hand side `of the piston cis also diminished. The spring f thus overcomes the counter-pressure, the p ump cut-ofi' device is brought into 'commumcatlon with v the atmosphere, and the alr-pump connected. This increases the pressure in the main air-reservoir until` the main reservoir-pressure no w actin f on the pistons b and c equalizes the fall o ressure in'the chamber 3,4and thus cuts o l the pump. By suitably selecting the'piston areas this overpressure above the normal main air-reservoirpressurecan` be soadjusted -that it is sutlicient'to release air-brakes, Fig. 2, the pressure of the mam air-reservoir 'conducted to the chamber lhere acts on -theentire lsurface of the piston b, and

the spring is chosen of such strength that it counterba ances this entire pressure when the pressure 1n the main reservoir 1s theanorm'alls,

f now on the normal pressure in the main air-reservoir being'reached the piston system, together with the valve e, is moved toward the right, the air-pumpwill be discon- -nected by flow of air into the passage B.

If compressed airis let into the brake-pipe D and chamber 3 for the purpose of applying the brakes, it will in conjunction with the spring f drive the pistons b c and valve e to- .Ward the left, and so connect lthe air-pump.y

yThe-pressure in the chamber 1 now increases until the O'Verpressure on thepiston b over- .tenevo f comes the press're on the pistons c 'and the force f the s ringv f and-again disconnects the pum he Lratio of thetwo piston areas in t is case also determines lthe extent of the overpressure .which may be produced in themain air-reservoir during the pioc'ess of'brakin V InsteatIof making use of rigid istonsother movable surfaces, such as eXible diaphragms, may be made use'of. I l

aving thus described my invention, .I claim as newf A pump-regulator for air-brakes compris# ing a casingof'vary-irg diameters,y twoistoits therein of different diameters divi ing the casing into threefchambers 1, 2, 3, the

-chambersl and 2 being on opposite sides'of the -large iston and ,the chamber 3 on the rear side o the small iston, a rod connecting the pistons together, u s on said rod, means for connecting the cham er 3 with the brakepipe, means for connecting the chamber 1 Wlth the main reservoir, a p ipe B connecting the chamberl withthe cut-off device of the pump, a pipeC adjacent said pipe B leading to the atmosphere, a slide-valve connected to the rod by the lugs thereon, said valve in one position connecting the pipe B with the pipe C and in itsother position permitting pipe B tocommunlcate with the `chambers 1 and 'a spring in chamber 2 for controlling the movement ofthe pistons.-

In witness whereof I have hereunto signed my name, this 23d day of May, 1905 in the presence of two subscrlbing witnesses.

WILHELM -I-IILDEBRAND.

Witnesses: HENRY HAsPEa,

vWOLDEMAR HAUPT. 

